I personally wouldn't use it with Spark and do you know why? Becuase:
1) I never use Sparks in my deck.
2) I wouldn't rely to Psi|Psi as a primary strategy of my deck, but as a secondary one instead. Let's say I play a mono-Aether rush with Psions, Phase Spiders, Fractals, Dim Shields and a few Psi. My opponent Plays with, let's say, a Scarab swarming deck and I am in danger of having all of my creatures devoured by them. So, I use 1 Psi and sacrifice 1 Psion or 1 Phase Spider in order to kill all the Scarabs before their hp exceed 4, and if I have a Lightning in my hand I can also kill the opponent's Pharaoh (4 mass CC damage + 5 single CC damage = 9 single CC damage = bye Pharaoh).